TEANSACTIONS OF THE SECTIONS. 



Section A.— MATHEMATICAL AND PHYSICAL SCIENCE. 



President of the Section, — Principal E. H, Griffiths, 

 M.A., D.Sc, F.R.S. 



THURSDAY, AUGUST 2. 

 The President delivered the following Address : — 



Mv predecessors in this Chair have in general been able to make commnnica- 

 tious to_ the Section conveyiug the results of investigations of their own, or 

 enunciating sorne principle which would throw a fresh light on the discoveries of 

 others. Mine is a far less happy lot. During the past four years and a half 

 I have been engaged in administrative duties of such a nature that no time has 

 been available for personal scientific work, and little energy even for the study of 

 the work of others. In these circumstances it might have seemed more fitting if 

 I had refused the honour which the Council of the British Association conferred 

 upon me by the request that I would undertake the arduous duties which fall to 

 thelot of the President of Section A. Nevertheless, after much hesitation, I 

 decided to accept the invitation, in the hope that as a looker-on at the struggle of 

 others, and with the experience of an old participator in the fray, I might be 

 able to communicate some impressions which had possibly escaped the notice of 

 those whose attention was necessarily more directed to some special branch of 

 inquiry. 



I trust that these words of apology may to some extent explain the nature of 

 what must appear a fragmentary discourse. 



In the interval which has elapsed since the last meeting of the Association 

 we have lost many men whose names were household words within the walls of 

 the physical laboratory. It is here only possible to briefly refer to the labours of 

 a few of those distinguished seekers after Natural Knowledge. 



The work of Dr. Sprengel has been by no means an unimportant factor in the 

 advance of our knowledge of radiant energy, ,c-rays, &c., if only on account of the 

 perfection of the apparatus for obtaining high vacua which will ever be associated 

 with his name. The practical effect of his discoveries was considerable, for the 

 business of electric lighting is undoubtedly gi-eatly indebted to his labours. Born 

 in 1834, he settled in England at the age of twenty-five. He was elected a Fellow 

 of the Royal Society in 1878, and resided in this country during the remaining 

 years of his life. 



The death of Charles Jasper Joly, F.R.S., at the early age of forty-one, robbed 

 mathematics and astronomy of one of their most devoted disciples. His ' Manual 

 of Quaternions ' is well known, and those acquainted with his astronomical work 

 are confident that, had his life been spared, he would, as Astronomer Royal of 

 Ireland, have added lustre to an office held by many distinguished predecessors. 



Samuel Pierpont Langley was born in 1834. In 1866 he became Director of 

 the Alleghany Observatory at Pittsburg. His first work was the institution of a 

 uniform system of time from the Atlantic seaboard to the Great Lakes. This, 

 the first successful attempt to introduce uniformity of time over a large area, waa 

 subsequently widely imitated. In 1880 he invented the bolometer, and thns 



